Shaft coupling

Abstract: The invention relates to a shaft coupling in which leaf spring members 12a through 12d, 14a through 14d, 16a through 16d, 18a through 18d are disposed on the rear surfaces of a driving side flange portion 2 and a driven side flange portion 4. One end of each leaf spring member taken in a circumferential direction is mounted to the flange portions 2, 4, and the other end is interconnected to the other end of the adjacent leaf spring member. At positions of the flange portions 2, 4 which correspond to a portion for interconnecting these leaf springs, hole portions 7a through 7d and the hole portions 9a through 9d being each disposed at the corresponding position. Torque transmitting rods 10a through 10d with a clearance through the corresponding hole portions, and interconnecting portions of the leaf spring members of the driving and driven side are each mounted to both ends of the torque transmitting rods.

Description: The present invention relates to a shaft coupling and, in particular, to a compact flexible shaft coupling which is easy of assembly and repair. In various mechanisms for transmitting a rotational torque, end portions of two rotational shafts are connected by means of a coupling. For example, an output rotational shaft of an engine or motor and an input rotational shaft of a pump are interconnected by means of the coupling. In this case, it calls for a considerable effort to install the engine or motor and the pump carefully so that the output rotational shaft of the engine or motor and the input rotational shaft of the pump may perfectly align with each other. Further, even if in that installation ample attention is paid to such an alignment, some eccentricity or angular deviation remains between both rotational shafts, and further, since vibrations occur in the engine, motor or pump during operation, in order to absorb these by means of the coupling portion, a flexible shaft coupling using flexible members such as springs, rubber pieces or the like has conventionally been used. A shaft coupling according to the preamble of claim 1 is known from EP-A-0 247 231. An object of the present invention is to provide a shaft coupling which is easy to assemble and to repair. Another object of the present invention is to provide a compact shaft coupling. A further object of the present invention is to provide a shaft coupling which allows the torque to be smoothly transmitted without great vibrations being transmitted. A still further object of the present invention is to provide a shaft coupling which may effectively cope with the eccentricity, the angular deviation and the axial displacement between the driving shaft side and the driven shaft side. In order to achieve the foregoing, according to the present invention, a shaft coupling is provided comprising the features of claim 1. Detailed embodiments of the invention are described in the dependent claims. According to the present invention, a shaft coupling can be provided which is easy of assemble and repair, and a compact coupling can be provided. Further, according to the present invention, a shaft coupling which is small in vibrations while torque is being transmitted and which can smoothly transmit the torque can be provided, and a shaft coupling which can effectively cope with the eccentricity, angular deviation and the axial displacement between the driving shaft and the driven shaft can be provided. Further, according to the present invention, since the relay member is interposed, a shaft coupling having a sufficient torsional rigidity can be obtained. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is an exploded perspective view illustrating a first embodiment of a shaft coupling according to the present invention; Fig. 2 is a perspective view of the shaft coupling of Fig. 1 which is in the assembled condition; and Fig. 3 is a partial cross-sectional view of the shaft coupling of Fig. 1; DESCRIPTION OF THE PREFERRED EMBODIMENTS Several specific embodiments according to the present invention are described with reference to the accompanying drawings. Fig. 1 is an exploded perspective view illustrating a shaft coupling according to the present invention, Fig. 2 is a perspective view of the same in the assembled condition and Fig. 3 is a partial cross-sectional view of the same. In these figures, reference numeral 2 denotes a flange portion at the side of the driving shaft, i.e. driving side flange portion, which is keyed to an end portion of the driving shaft (not shown). 2' denotes a rotational axis of the driving shaft. 4 denotes a flange portion at the side of the driven shaft, i.e. driven side flange portion, which is keyed to an end portion of the driven shaft (not shown). 4' denotes a rotational axis of the driven shaft. The rotational axis 2' of the driving shaft and the rotational axis 4' of the driven shaft substantially align with each other. In consequence, the end surface (front surface) of the driving side flange portion 2 which faces the driven side flange portion 4 and the end surface (front surface) of the driven side flange portion 4 which faces the driving side flange portion 2 run in substantially parallel to each other. Through the driving side flange portion 2, four axially threaded holes 6a, 6b, 6c, 6d, which are each disposed evenly in the circumferential direction, and four axial hole portions 7a, 7b, 7c, 7d (not shown) disposed evenly in the circumferential direction are formed. The positions of these eight threaded holes or hole portions are allocated evenly in the circumferential direction. Similarly, through the driven side flange portion 4, four axially threaded holes 8a, 8b, 8c, 8d disposed evenly in the circumferential direction and four axial hole portions 9a, 9b, 9c, 9d disposed evenly in the circumferential direction are formed. The positions of these eight threaded holes or hole portions are evenly disposed in the circumferential direction. Further, four axially threaded holes 6a, 6b, 6c, 6d of the driving side flange portion 2 and four axially threaded holes 8a, 8b, 8c, 8d of the driven side flange portion 4 are each positioned axially corresponding to each other, and four axial hole portions 7a, 7b, 7c, 7d of the driving side flange portion 2 and four axial hole portions 9a, 9b, 9c, 9d of the driven side flange portion 4 are each positioned axially corresponding to each other. Torque transmitting rods 10a, 10b, 10c, 10d are each disposed to pass through each of the axial hole portions 7a, 7b, 7c, 7d of the driving side flange portion 2 and each of the corresponding axial hole portions 9a, 9b, 9c, 9d of the driven side flange portion 4. Through the foregoing rods, threaded holes are each formed passing through axially. On a rear surface of the driving side flange portion 2, eight arcuate driving side leaf spring members 12a, 12b, 12c, 12d, 14a, 14b, 14c, 14d are circumferentially disposed. These leaf spring members each have a hole at their each end, and adjacent ones are overlapped at the end portions so that the holes align with each other. The hole at one end of each leaf spring member is positioned at the position of the driving side flange portion 2 which corresponds to the axial threaded hole and, by screwing a bolt into the threaded hole, the leaf spring member is mounted to the driving side flange portion 2. Further, the hole of the other end of each leaf member is positioned at a position corresponding to the rod together with the hole of the other end of the adjacent leaf spring member, and by screwing a bolt into the threaded hole of the rod, the leaf spring member is mounted at the end portion of the driving side of the rod. As shown, when they are mounted, a washer is interleaved therebetween. On a rear surface of the driven side flange portion 4, eight arcuate driven side leaf spring members 16a, 16b, 16c, 16d, 18a, 18b, 18c, 18d are circumferentially disposed. These driven side leaf spring members are also mounted to the driven side flange portion 4 and the torque transmitting rod, as in the driving side leaf spring members. Fig. 3 illustrates how each member is mounted in the neighborhood of the rod 10a. As shown, the rod 10a has an outer diameter smaller than the inner diameter of the hole portions 7a, 9a through which the rod passes, and has a length greater than the interval between the rear surfaces of the driving side flange portion 2 and driven side flange portion 4. The same is also the case with other rods. The shaft coupling according to this embodiment may be readily made by assembling the members, as illustrated in Fig. 1. Incidentally, as the leaf spring member, one comprising a single leaf spring may be used, or ones comprising a plurality of leaf springs laminated together may be used. Further, depending on the magnitude of the torque to be transmitted, as the leaf spring member, ones made of a reinforced plastic, which is favorable for lightening weight, may be used other than one made of metal. In this embodiment, when the driving side flange portion 2 is rotated, torque is transmitted through the leaf spring members 12a through 12d, 14a through 14d to the rods 10a through 10d, from which it is transmitted through the leaf spring members 16a through 16d, 18a through 18d to the driven side flange portion 4. Based on the deformations such as bend or twist of each spring member, the following relative movements each becomes possible between the driving side flange portion 2 and the driven side flange portion 4 within an appropriate range: 1. rotation around the axial direction; 2. axial movement; 3. movement within a plane intersecting at a right angle with the axial direction; and 4. rotation which tilts the rotational axis 2' of the driving shaft relative to the rotational axis 4' of the driven shaft. Thus, by suppressing transmission of vibration between the driving side flange portion 2 and the driven side flange portion 4, the torque can be smoothly transmitted and, even if the eccentricity, angular deviation or axial displacement takes place between the sides of the driving shaft and the driven shaft, they can be absorbed. Incidentally, the interval between the driving side flange portion 2 and the driven side flange portion 4 is set so as not to prevent the foregoing relative movements between the driving side flange portion 2 and the driven side flange portion 4, which is expected to occur during the operation. Further, the size of each axial hole portion 7a, 7b, 7c, 7d of the driving side flange portion 2 and the size of each axial hole portion 9a, 9b, 9c, 9d of the driven side flange portion 4 are each set with an allowance so as not to prevent the foregoing relative movements between the driving side flange portion 2 and the driven side flange portion 4, which is anticipated to occur during the operation. In place of the hole portion, a notched portion notched outwardly of the flange portion may also be formed. In the forgoing embodiment, since only one type of the leaf spring members 12a through 12d, 14a through 14d, 16a through 16d, 18a through 18d may be used, the number of types of the components may be small. If either one of the leaf spring members or the torque transmitting rods is damaged, it is easy to replace by extracting the bolt at the corresponding part and the repair is simple. Further, in the foregoing embodiment, since the leaf spring member is mounted on the rear surface of the driving side flange portion 2 and the driven side flange portion 4, the axial dimension can be made smaller for compactness by making the front surface of the driving side flange portion 2 and the front surface of the driven side flange portion 4 sufficiently close.

Claims: Shaft coupling in which: a driving side flange portion (2) and a driven side flange portion (4) are opposed to each other; a plurality of driving side leaf spring members (12a-12d, 14a-14d) are circumferentially disposed on a rear surface of the driving side flange portion (2) being positioned opposite to a front surface of the driving side flange portion (2) which faces said driven side flange portion (4), one end of each of said driving side leaf spring members (12a-12d, 14a-14d) taken in the circumferential direction being mounted at the driving side flange portion (2), the other end of each of said driving side leaf spring members (12a-12d, 14a-14d) taken in the circumferential direction being connected to the other end of the adjacent driving side leaf spring member (12a-12d, 14a-14d) taken in the circumferential direction, a plurality of hole portions (7a-7d) or notched portions which pass through in an axial direction being provided at the position of the driving side flange portion (2) which corresponds to an interconnecting portion of the driving side leaf spring members (12a-12d, 14a-14d); a plurality of driven side leaf spring members (16a-16d, 18a-18d) are circumferentially disposed on a rear surface of said driven side flange portion (4), said rear surface of the driven side flange portion (4) being positioned opposite to a front surface of the driven side flange portion (4) which faces said driving side flange portion (2), one end of each of said driven side leaf spring members (16a-16d, 18a-18d) taken in the circumferential direction being mounted at the driven side flange portion (4) taken in the circumferential direction, the other end of each of said driven side leaf spring members (16a-16d, 18a-18d) taken in the circumferential direction being connected to the other end of the adjacent driven side leaf spring member (16a-16d, 18a-18d) taken in the circumferential direction, a plurality of hole portions (9a-9d) or notched portions which pass through in an axial direction being provided at the position of the driven side flange portion (4) which corresponds to an interconnecting portion of the driven side leaf spring members (16a-16d, 18a-18d); and said hole portions (7a-7d) or notched portions of said driving side flange portion (2) and said hole portions (9a-9d) or notched portions of said driven side flange portion (4) are each disposed at corresponding positions, characterized in that a plurality of torque transmitting rods (10a-10d) is provided, each of which axially passes with an allowance through the corresponding hole portions (7a-7d, 9a-9d) or notched portions of the driving side flange portion (2) and driven side flange portion (4), said interconnecting portion to the driving side leaf spring members (12a-12d, 14a-14d) being mounted to one end of each of said torque transmitting rods (10a-10d) and said interconnecting portion of the driven side leaf spring members (16a-16d, 18a-18d) being mounted to the other end thereof. Shaft coupling as set forth in claim 1, characterized in that the driving side (12a-12d, 14a-14d) or driven side leaf spring member (16a-16d, 18a-18d) is disposed in substantially parallel to the rear surface of the driving side (2) or driven side flange portion (4), one end of the driving side (12a-12d, 14a-14d) or driven side leaf spring member (16a-16d, 18a-18d) is mounted to the driving side (2) or driven side flange portion (4) by means of a bolt, an interconnection of the other ends of the driving side (12a-12d, 14a-14d) or driven side leaf spring members (16a-16d, 18a-18d) and a mounting of the interconneting portion of the driving side (12a-12d, 14a-14d) or driven side leaf spring members (16a-16d, 18a-18d) to one end or the other end of the torque transmitting rod (10a-10d) being achieved by means of a bolt. Shaft coupling as set forth in claim 1, characterized in that a mounting of one end of each driving side leaf spring members (12a-12d, 14a-14d) to said driving side flange portion (2) and a mounting of one end of the adjacent driving side leaf spring member (12a-12d, 14a-14d) to said driving side flange portion (2) are each achieved at the same position, and, a mounting of one end of each driven side leaf spring members (16a-16d, 18a-18d) to said driven side flange portion (4) and a mounting of one end of the adjacent driven side leaf spring member (16a-16d, 18a-18d) to said driven side flange portion (4) are each achieved at the same position.

Inventors: KURIBAYASHI SADATOMO, KURIBAYASHI, SADATOMO
Applicants: K SEVEN KK, KAY SEVEN CO., LTD.
Application year: 1994
Main classification: F16D3
IPC codes: F16D3